
Device Operation (Continued)
OUTPUT INTERFACING
The CLC001 has two complementary, ground referenced
outputs designed to drive AC-coupled and terminated 75Ω
coaxial cables. The outputs are single ended; however, they
could be treated as a single differential output as long as
current paths from each output go to ground.
The output of the CLC001 is a high impedance current
source. It expects to see a 75Ωshunt resistor before driving
cable to convert the current output to a voltage and provide
proper back-matching. No series back-matching resistors
should be used. Refer to Section Typical Application for an
illustration.
Output levels range from 800 mV
p-p
to 1.0 V
p-p
±10% into
75ΩAC-coupled, back-matched loads. Output level is con-
trolled by the value of R
REF
connected to pin 4. R
REF
is 1.91
kΩ±1% for 800 mV
p-p
, and 1.5 kΩ±1% for 1.0 V
p-p
. Refer
to Figure 10 for the output level’s sensitivity to R
REF
.
Evaluation Board
Evaluation boards are available for a nominal charge that
demonstrate the basic operation of the SDI/SDV/SDH de-
vices. The evaluation boards can be ordered through Nation-
al’s Distributors. Supplies are limited, please check for cur-
rent availability.
The SD001EVK evaluation kit for the CLC001, Serial Digital
Cable Driver with Adjustable Outputs, provides an operating
environment in which the cable driver can be evaluated by
system / hardware designers. The evaluation board has all
the needed circuitry and connectors for easy connection and
checkout of the device circuit options as discussed in the
CLC001 datasheet. A schematic, parts list and pictorial
drawing are provided with the board.
From the WWW, the following information may be viewed /
downloaded for most evaluation boards: www.national.com/
appinfo/interface
•Device Datasheet and / or EVK User Manual
•View a picture of the EVK
•View the EVK Schematic
•View the top assembly drawing and BOM
•View the bottom assembly drawing and BOM
PCB Layout Recommendations
Printed circuit board layout affects the performance of the
CLC001. The following guidelines will aid in achieving satis-
factory device performance.
•Use a ground plane or power/ground plane sandwich
design for optimum performance.
•Bypass device power with a 0.01 µF monolithic ceramic
capacitor in parallel with a 6.8 µF tantalum electrolytic
capacitor located no more than 0.1" (2.5 mm) from the
device power pins.
•Provide short, symmetrical ground return paths for:
— inputs,
— supply bypass capacitors and
— the output load.
•Provide short, grounded guard traces located
— under the centerline of the package,
— 0.1" (2.5 mm) from the package pins
— on both top and bottom of the board with connecting
vias.
10132913
FIGURE 10. Output level’s sensitivity to R
REF
CLC001
www.national.com 10